btrfs: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <amwang@redhat.com>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index d02c27c..b805afb 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -120,10 +120,10 @@
 		page = cb->compressed_pages[i];
 		csum = ~(u32)0;
 
-		kaddr = kmap_atomic(page, KM_USER0);
+		kaddr = kmap_atomic(page);
 		csum = btrfs_csum_data(root, kaddr, csum, PAGE_CACHE_SIZE);
 		btrfs_csum_final(csum, (char *)&csum);
-		kunmap_atomic(kaddr, KM_USER0);
+		kunmap_atomic(kaddr);
 
 		if (csum != *cb_sum) {
 			printk(KERN_INFO "btrfs csum failed ino %llu "
@@ -521,10 +521,10 @@
 			if (zero_offset) {
 				int zeros;
 				zeros = PAGE_CACHE_SIZE - zero_offset;
-				userpage = kmap_atomic(page, KM_USER0);
+				userpage = kmap_atomic(page);
 				memset(userpage + zero_offset, 0, zeros);
 				flush_dcache_page(page);
-				kunmap_atomic(userpage, KM_USER0);
+				kunmap_atomic(userpage);
 			}
 		}
 
@@ -993,9 +993,9 @@
 		bytes = min(PAGE_CACHE_SIZE - *pg_offset,
 			    PAGE_CACHE_SIZE - buf_offset);
 		bytes = min(bytes, working_bytes);
-		kaddr = kmap_atomic(page_out, KM_USER0);
+		kaddr = kmap_atomic(page_out);
 		memcpy(kaddr + *pg_offset, buf + buf_offset, bytes);
-		kunmap_atomic(kaddr, KM_USER0);
+		kunmap_atomic(kaddr);
 		flush_dcache_page(page_out);
 
 		*pg_offset += bytes;